Polyphenyl ether conductive composite material and preparation method therefor

Abstract

The present application relates to the technical field of engineering plastics and provides a polyphenyl ether conductive composite material and a preparation method therefor. In the polyphenyl ether conductive composite material provided by the present application, a carbon nanotube composite material, instead of a traditional carbon-based conductive agent, is added to a resin base material as a conductive filler, so that the addition amount of the conductive filler is reduced; in addition, because a carbon nanotube has a fibrous structure, the wear resistance of the material can be improved, thereby achieving a dust shedding reduction effect. The modified carbon nanotube in the present application comprises a mixture of a multi-walled carbon nanotube, graphene, and calcium silicate, wherein the graphene, which has a two-dimensional structure, can improve the interface energy between the carbon nanotube and the resin base material; in addition, the calcium silicate can fill gaps between the carbon nanotube and the graphene and the resin base material, thereby reducing stripping between the carbon nanotube and the base material, leading to tight connection. Moreover, by forming the modified carbon nanotubes and the polystyrene into a composite material, the present application exhibits improved dispersion of the carbon nanotube and improved processing performance.

Description

Polyphenyl ether conductive composite material and preparation method thereof TECHNICAL FIELD

[0001] The present application belongs to the technical field of engineering plastics, and particularly relates to a polyphenyl ether conductive composite material and a preparation method thereof. BACKGROUND

[0002] High-performance integrated circuits have thousands of circuits inside, and the internal circuits are complex, fine and precise. These fine and precise circuits etched and buried on silicon-based semiconductor wafers must be properly protected to prevent damage during production and transportation. Chip trays are widely used in semiconductor chip manufacturing, testing and packaging, etc. They can protect chips from static electricity, vibration and high temperature, etc. and ensure the quality and reliability of the chips. Therefore, the tray material needs to have excellent static dissipation capacity.

[0003] Semiconductor chip trays and integrated circuit tray materials need to have excellent mechanical properties, good static dissipation capacity, high heat resistance, dimensional stability, small warpage and other characteristics. Polyphenyl ether resin (PPO) has excellent mechanical properties, heat resistance, electrical insulation and the advantage of less creep at high temperatures. At the same time, PPO has lower density and moisture absorption, higher strength, and better dimensional stability. Existing semiconductor trays and integrated circuit trays mainly use PPO, polysulfone (PSF) or polyether sulfone (PES) as the base material.

[0004] In order to provide conductivity to the tray and prevent the tray from accumulating static electricity, the traditional method is to add conductive fillers such as carbon black or carbon fibers to the base resin material. Although carbon fibers have a reinforcing effect on the resin, the amount of carbon fibers added is large, and the cost pressure is great. Carbon black is relatively low in price, but the addition amount is generally about 20%-30% by mass, which causes serious dusting phenomenon, which can cause IC burnout and lead to low process yield. SUMMARY

[0005] The purpose of the present application is to provide a polyphenyl ether conductive composite material and a preparation method thereof, which aims to solve the problem of large amount of conductive filler added in the existing tray material and serious dusting phenomenon. TECHNICAL SOLUTION

[0006] To achieve the above application purpose, the technical scheme adopted by the present application is as follows:

[0007] In a first aspect, the present application provides a polyphenyl ether conductive composite material, which comprises the following components by weight:

[0008] Polyphenyl ether 40-70 parts;

[0009] Carbon nanotube composite material 10-30 parts;

[0010] Toughening agent 1~3 parts;

[0011] Dispersant 2~4 parts;

[0012] Inorganic filler 20~30 parts;

[0013] Antioxidant 0.1~1 part;

[0014] The carbon nanotube composite material comprises modified carbon nanotubes and high impact polystyrene, and the modified carbon nanotubes comprise multi-walled carbon nanotubes, graphene and calcium silicate.

[0015] In some embodiments, the mass ratio of the modified carbon nanotubes and the high impact polystyrene is (10~20):(80~90).

[0016] In some embodiments, the mass ratio of the multi-walled carbon nanotubes, the graphene and the calcium silicate is 1:(0.1~0.5):(0.5~2).

[0017] In some embodiments, the multi-walled carbon nanotubes have at least one of the following (1)-(5):

[0018] (1) The multi-walled carbon nanotubes have an inner diameter of 1~2nm, an outer diameter of 8~25nm, a length of 1~100μm, an aspect ratio of 5000~10000:1, a bulk density of 0.15~0.4g / cm 3 , and a specific surface area of 190~270m 2 / g.

[0019] (2) The multi-walled carbon nanotubes have a thermal conductivity of 300~6000W / mk.

[0020] (3) The multi-walled carbon nanotubes have an initial decomposition temperature of 500~600℃.

[0021] (4) The multi-walled carbon nanotubes have a particle size D97≤50μm and a particle size Dmax≤300μm.

[0022] (5) The multi-walled carbon nanotubes have a powder resistivity of 30~60mΩ·cm.

[0023] (6) The multi-walled carbon nanotubes have a Raman spectrum intensity ratio I D / I G ≤1.2.

[0024] In some embodiments, the high impact polystyrene has a weight average molecular weight of 150,000-300,000 g / mol.

[0025] In some embodiments, the inorganic filler includes at least one of talcum powder, calcium carbonate, silica powder, mica powder, kaolin, wollastonite, and attapulgite; and the inorganic filler has a particle mesh number of 1,000-3,000.

[0026] In some embodiments, the antioxidant includes at least one of a hindered phenol antioxidant and a phosphite antioxidant.

[0027] In some embodiments, the polyphenylene ether conductive composite has at least one of (1)-(3) as follows:

[0028] (1) the polyphenylene ether conductive composite has a surface resistivity of 10 6 ~10 8 Ω / sq;

[0029] (2) the polyphenylene ether conductive composite has a melt index of 6-13 g / 10 min under a test condition of 300°C and 10 kg;

[0030] (3) the polyphenylene ether conductive composite has a density of 1.07-1.1 g / cm 3 .

[0031] In a second aspect, the present application provides a preparation method of a polyphenylene ether conductive composite, including the following steps:

[0032] mixing and treating the multi-walled carbon nanotubes, the graphene, and the calcium silicate to obtain modified carbon nanotubes;

[0033] dispersing and treating the modified carbon nanotubes and the high impact polystyrene to obtain a carbon nanotube composite;

[0034] mixing the carbon nanotube composite, the polyphenylene ether, the toughening agent, the dispersant, the inorganic filler, and the antioxidant, and then melt-extruding and granulating to obtain the polyphenylene ether conductive composite.

[0035] In some embodiments, the step of mixing and treating the multi-walled carbon nanotubes, the graphene, and the calcium silicate to obtain modified carbon nanotubes includes: mixing the multi-walled carbon nanotubes, the graphene, the calcium silicate, a binder, and a solvent, and then performing ball milling to obtain a mixed slurry, and drying the mixed slurry to obtain the modified carbon nanotubes.

[0036] In some embodiments, the conditions of the ball milling treatment include that the grinding medium comprises zirconia balls and / or agate balls; the size of the grinding medium is 0.5-1.0 mm; the filling rate of the grinding medium is 60%-85%; and the stirring rate is 500-900 r / min.

[0037] In some embodiments, the step of dispersing the modified carbon nanotubes and the high-impact polystyrene to obtain the carbon nanotube composite material comprises: dispersing the modified carbon nanotubes and the high-impact polystyrene in tetrahydrofuran, and obtaining the carbon nanotube composite material after vacuum removal of the solvent.

[0038] In some embodiments, the process conditions of the melt extrusion granulation include that the extrusion temperature is 250-300℃, the main machine rotation speed is 400-1000 rpm / min, and the melt extrusion granulation is performed by a double-screw extruder.

[0039] The polyphenyl ether conductive composite material provided in the first aspect of the application uses a modified carbon nanotube composite material to replace a traditional carbon-based conductive agent as a conductive filler added to a resin base material. Since the amount of the modified carbon nanotube added is only 1 / 10 of the amount of carbon black added, and since the carbon nanotube has a fibrous structure, the wear resistance of the material can be improved, thereby achieving the purpose of lower dust falling. The modified carbon nanotube in the application comprises a multi-walled carbon nanotube, graphene and calcium silicate. The multi-walled carbon nanotube serves as a one-dimensional conductive filler, and cooperates with the graphene having a two-dimensional structure. The graphene can improve the interfacial energy between the carbon nanotube and the resin base material to a certain extent. At the same time, the calcium silicate can fill the gaps between the carbon nanotube, the graphene and the resin base material, reduce the peeling between the carbon nanotube and the base material, and connect closely. Moreover, the modified carbon nanotube is formed into a composite material with polystyrene. The composite material is a high-uniformity antistatic material, is easy to add and disperse, further improves the dispersion of the carbon nanotube, and improves the processing performance.

[0040] The preparation method of the polyphenyl ether conductive composite material provided in the second aspect of the application. The preparation method mixes a multi-walled carbon nanotube with graphene and calcium silicate to obtain a modified carbon nanotube, improves the interfacial energy between the carbon nanotube and the resin base material, then composites the modified carbon nanotube with high-impact polystyrene to obtain a composite material, improves the dispersibility of the carbon nanotube, and finally mixes the modified carbon nanotube composite material with other raw materials to melt and granulate to obtain the polyphenyl ether conductive composite material. The preparation method is simple to operate, has strong operability, is easy to control the quality of the product, and has low cost. Embodiments of the application

[0041] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0042] It should be noted that when a component is referred to as being "fixed to" or "set to" another component, it can be directly on the other component or indirectly on the other component. When a component is referred to as being "connected to" another component, it can be directly or indirectly connected to the other component. The terms "upper", "lower", "left", "right", etc. indicate the orientation or positional relationship shown in the drawings, and are only used for convenience of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. For those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "first", "second" are only used for the purpose of convenience of description, and cannot be understood as indicating or implying relative importance or implying the number of technical features. The meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0043] The semiconductor chip tray requires materials to have the characteristics of electrical conductivity, anti-static property, high temperature resistance, high strength, etc. In order to make the tray have electrical conductivity and at the same time have anti-static property, the traditional method is to add carbon black or carbon fiber to the resin base material of the tray, but the addition amount of carbon black and carbon fiber is large, the dusting is serious, and the cost is high.

[0044] Based on this, the first aspect of the embodiments of the present application provides a polyphenyl ether conductive composite material, which comprises the following components by weight:

[0045] Polyphenyl ether 40-70 parts;

[0046] Carbon nanotube composite material 10-30 parts;

[0047] Toughening agent 1-3 parts;

[0048] Dispersing agent 2-4 parts;

[0049] Inorganic filler 20-30 parts;

[0050] Antioxidant 0.1-1 part;

[0051] Among them, the carbon nanotube composite material includes modified carbon nanotubes and high-impact polystyrene; the modified carbon nanotubes include multi-walled carbon nanotubes, graphene and calcium silicate.

[0052] The first aspect of the present application provides a polyphenylene ether conductive composite material, which uses modified carbon nanotubes to replace traditional carbon-based conductive agents as conductive fillers to be added to the resin substrate. Since the amount of modified carbon nanotubes added is only 1 / 10 of the amount of carbon black added, and since the carbon nanotubes have a fibrous structure, the wear resistance of the material can be effectively improved, thereby achieving the purpose of lower dusting. The modified carbon nanotubes of the present application include multi-walled carbon nanotubes, graphene and calcium silicate, wherein the multi-walled carbon nanotubes are used as one-dimensional conductive fillers, combined with graphene with a two-dimensional structure, graphene can improve the interfacial energy between the carbon nanotubes and the resin substrate to a certain extent, and calcium silicate can fill the gaps between the carbon nanotubes and the graphene and the resin substrate, further reducing the peeling between the carbon nanotubes and the substrate, and the connection is tight. Moreover, the present application forms a composite material with modified carbon nanotubes and polystyrene. The composite material is an antistatic material with a high degree of uniformity, which is easy to add and easy to disperse, thereby improving the dispersion of carbon nanotubes and improving processing performance. The components of the embodiments of the present application also include polyphenylene ether (PPO), one of the five most common engineering plastics. Polyphenylene ether has one of the lowest dielectric constants and dielectric loss among engineering plastics, is virtually unaffected by temperature and humidity, and exhibits excellent properties such as high-temperature resistance, low warpage, good stability, and antistatic properties. When the components of the polyphenylene ether conductive composite material are within the aforementioned ranges, a polyphenylene ether conductive composite material for pallets can be obtained that exhibits both excellent antistatic and electrical conductivity.

[0053] In some embodiments, the weight percentage of the polyphenylene ether includes, but is not limited to, any of 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, and 70 parts, or any range therebetween. In the embodiments of the present application, the weight percentage of the polyphenylene ether is controlled within the above range, and specific weight percentages of other components such as the carbon nanotube composite material, toughening agent, and inorganic filler are compounded to produce a polyphenylene ether conductive composite material with excellent wear resistance, low dust emission, and good uniformity.

[0054] In some embodiments, the carbon nanotube composite material includes modified carbon nanotubes and high-impact polystyrene, wherein the mass ratio of the modified carbon nanotubes to the high-impact polystyrene is (10-20):(80-90).

[0055] As an example, the mass ratio of the modified carbon nanotubes and the high-impact polystyrene can be 10:90, 12:88, 14:86, 16:84, 18:82, 20:80, and the like typical but non-limiting values. By controlling the mass ratio of the modified carbon nanotubes and the high-impact polystyrene within the above range, the dispersibility of the modified carbon nanotubes can be further improved, and the processing performance can be improved.

[0056] In some embodiments, the modified carbon nanotubes include multi-walled carbon nanotubes, graphene, and calcium silicate. The mass ratio of the multi-walled carbon nanotubes, graphene, and calcium silicate is 1:(0.1-0.5):(0.5-2). As an example, the mass ratio of the multi-walled carbon nanotubes, graphene, and calcium silicate can be 1:0.1:0.5, 1:0.2:0.6, 1:0.3:0.8, 1:0.4:1.0, 1:0.5:1.5, 1:0.5:2, and the like typical but non-limiting values. By controlling the mass ratio of the multi-walled carbon nanotubes, graphene, and calcium silicate within the above range, the interfacial energy of the carbon nanotubes and the resin substrate can be better improved, and the peeling between the carbon nanotubes and the substrate can be further reduced, and the dusting phenomenon can be reduced.

[0057] In some embodiments, the multi-walled carbon nanotubes have an inner diameter of 1-2 nm, an outer diameter of 8-25 nm, a length of 1-100 μm, an aspect ratio of 5000-10000:1, and a bulk density of 0.15-0.4 g / cm 3 , and a specific surface area of 190-270 m 2 / g. As an example, the aspect ratio of the multi-walled carbon nanotubes can be any one of 5000, 6000, 7000, 8000, 9000, 10000 or a range value between any two of them. The aspect ratio of the carbon nanotubes is one of the core indicators affecting the conductivity, which directly determines the product performance of the carbon nanotubes. The thinner the carbon nanotube diameter and the longer the length, the better the conductivity.

[0058] In some embodiments, the multi-walled carbon nanotubes have a thermal conductivity of 300-6000 W / mk. As an example, the thermal conductivity of the multi-walled carbon nanotubes can be any one of 300 W / mk, 1000 W / mk, 2000 W / mk, 3000 W / mk, 4000 W / mk, 5000 W / mk, 6000 W / mk or a range value between any two of them. The thermal conductivity of the carbon nanotubes is closely related to its structure and size, and by controlling the thermal conductivity of the multi-walled carbon nanotubes within the above range, the purpose of controlling the purity, length, and other properties of the carbon nanotubes can be achieved.

[0059] In some embodiments, the initial decomposition temperature of the multi-walled carbon nanotubes is 500-600°C. As an example, the initial decomposition temperature of the multi-walled carbon nanotubes can be any one of 500°C, 510°C, 520°C, 530°C, 540°C, 550°C, 560°C, 570°C, 580°C, 590°C, 600°C or a range value between any two of them. The initial decomposition temperature of the carbon nanotubes is affected by its thermal stability, structure, impurities and defects, controlling the initial decomposition temperature of the multi-walled carbon nanotubes in the above range can also evaluate the specifications and quality of the carbon nanotubes, and thus can also be used as a basis for material selection.

[0060] In some embodiments, the particle size D97 of the multi-walled carbon nanotubes is ≤50μm, and the particle size Dmax is ≤300μm. The particle size D97 refers to the particle size corresponding to the cumulative particle size distribution of 97% of a sample. Its physical meaning is that the particles with a particle size smaller than it account for 97%. This is a widely used data to represent the coarse end particle size index of the powder. The particle size Dmax represents the largest particle size in the particle size distribution, which can reflect the largest particle size in the particle sample and to some extent reflect the width of the particle size distribution range. The particle size Dmax in combination with the particle size D97 can effectively evaluate the characteristics and quality of the carbon nanotube particles.

[0061] In some embodiments, the powder resistivity of the multi-walled carbon nanotubes is 30-60mΩ·cm. As an example, the powder resistivity of the multi-walled carbon nanotubes can be any one of 30mΩ·cm, 35mΩ·cm, 40mΩ·cm, 45mΩ·cm, 50mΩ·cm, 55mΩ·cm, 60mΩ·cm or a range value between any two of them. The resistivity of the carbon nanotubes represents the resistance encountered by the current passing through a unit length of the carbon nanotubes, which is determined by the structure and conductive properties of the carbon nanotubes. Controlling the powder resistivity of the multi-walled carbon nanotubes in the above range can further improve the conductive performance of the polyphenyl ether conductive composite material.

[0062] In some embodiments, the Raman spectrum intensity ratio I D / I G of the multi-walled carbon nanotubes is ≤1.2. The Raman spectrum can characterize the structural information such as the lattice defects and morphology of the carbon nanotubes. The I D / I G ratio is related to the structural disorder and damage of the carbon nanotubes, and this ratio can be used to describe the defects of the crystal. The larger the ratio, the more defects the crystal has. Selecting the multi-walled carbon nanotubes with a Raman spectrum intensity ratio in the above range can further control the quality of the multi-walled carbon nanotubes and reduce defects.

[0063] In some embodiments, the high impact polystyrene has a weight average molecular weight of 150,000-300,000 g / mol. As an example, the high impact polystyrene can have a weight average molecular weight of any one of 150,000-200,000 g / mol, 180,000-250,000 g / mol, 230,000-280,000 g / mol, 250,000-300,000 g / mol, or a range between any two of them. The weight average molecular weight can reflect the length of the polymer chain and the molecular weight distribution. The weight average molecular weight is often used to evaluate the mechanical properties and processing properties of the polymer. The use of the high impact polystyrene in the above range of weight average molecular weight can not only better improve the dispersibility and processability of the carbon nanotubes, but also better improve the processability of the polyphenylene ether, so that the prepared polyphenylene ether conductive composite has better performance.

[0064] In some embodiments, the toughening agent includes at least one of a maleic anhydride grafted hydrogenated styrene-butadiene-styrene copolymer, a succinic anhydride grafted hydrogenated styrene-butadiene-styrene copolymer, a maleic anhydride grafted hydrogenated styrene-isoprene-styrene copolymer, and a succinic anhydride grafted hydrogenated styrene-isoprene-styrene copolymer. The above toughening agent can improve the dispersibility and interfacial compatibility of the inorganic powder in the resin matrix, and improve the impact resistance of the composite.

[0065] In some embodiments, the dispersant includes at least one of polyvinylpyrrolidone, fatty alcohol polyoxyethylene ether, sodium dodecyl benzene sulfonate, and sodium dodecyl sulfate. The above dispersant has excellent performance of efficient cleaning and stable dispersion. The addition of at least one of the above dispersants can further improve the dispersibility of the carbon nanotubes, inorganic fillers, and the like in the resin material.

[0066] In some embodiments, the inorganic filler includes at least one of talc, calcium carbonate, silica powder, mica powder, kaolin, wollastonite, and attapulgite. The above inorganic filler has the performance characteristics of high hardness, high wear resistance, and high temperature resistance. The use of the above inorganic filler can better improve the strength and hardness of the polyphenylene ether conductive composite, and improve the wear resistance. In some embodiments, the inorganic filler has a particle mesh number of 1000-3000 meshes. As an example, the inorganic filler can have a particle mesh number of any one of 1000 meshes, 1300 meshes, 1500 meshes, 1800 meshes, 2000 meshes, 2300 meshes, 2500 meshes, 2800 meshes, and 3000 meshes, or a range between any two of them. The particle mesh number of the filler reflects the particle size. The larger the mesh number, the smaller the particle size, the larger the contact area with the substrate, and the larger the filling density.

[0067] In some embodiments, the antioxidant includes at least one of hindered phenolic antioxidant, phosphite antioxidant. As an example, the antioxidant can include at least one of Irganox 1010, Irganox 168, Irganox 1076, Irganox 1330, Irganox 1035, Irganox 3144, Irganox 1024, and Irganox 126. The above-mentioned antioxidants can be selected to better inhibit or slow down the aging degradation of the polyphenylene ether conductive composite.

[0068] In some embodiments, the surface resistivity of the top surface and the bottom surface of the molded product made of the polyphenylene ether conductive composite of the present application is 10 6 ~10 8 Ω / sq. The surface resistivity is a physical quantity for measuring the surface conductive performance of an object. The polyphenylene ether conductive composite of the present application requires antistatic, and the surface resistivity of the top surface and the bottom surface of the product made of the polyphenylene ether conductive composite of the present application is within the above range, which meets the performance requirements of the semiconductor tray.

[0069] In some embodiments, the melt index of the polyphenylene ether conductive composite of the present application is 6-13 g / 10 min under the test condition of 300℃ and 10 kg. The melt index is an index for measuring the flowability of a thermoplastic material in a molten state. The melt index of a material can be used as an important parameter for measuring the flowability during molding, the size of the molecular weight of the material, and the molding process conditions. The polyphenylene ether conductive composite within the above melt index range is suitable for the production of semiconductor trays.

[0070] In some embodiments, the density of the polyphenylene ether conductive composite of the present application is 1.07-1.1 g / cm 3 . The polyphenylene ether conductive composite has the advantage of low density, low weight, and high strength, which meets the performance requirements of the semiconductor tray.

[0071] The second aspect of the present application provides a preparation method of a polyphenylene ether conductive composite, including the following steps:

[0072] S1: mixing and treating multi-walled carbon nanotubes with graphene and calcium silicate to obtain modified carbon nanotubes;

[0073] S2: dispersing and treating the modified carbon nanotubes and high-impact polystyrene to obtain a carbon nanotube composite;

[0074] S3: mixing the carbon nanotube composite with polyphenylene ether, toughening agent, dispersant, inorganic filler, and antioxidant, and then melt extruding and granulating to obtain a polyphenylene ether conductive composite.

[0075] The preparation method of the polyphenyl ether conductive composite material provided in the second aspect of the embodiments of the present application improves the interface energy between the carbon nanotubes and the resin base material by mixing the multi-walled carbon nanotubes with the graphene and the calcium silicate to obtain modified carbon nanotubes, then improves the dispersibility of the carbon nanotubes by compounding the modified carbon nanotubes with the high-impact polystyrene to obtain a composite material, and finally obtains the polyphenyl ether conductive composite material by mixing and melt granulating the modified carbon nanotube composite material and other raw materials. The preparation method is simple to operate and has strong operability, is easy to control the product quality, and has low cost.

[0076] Step S1:

[0077] The multi-walled carbon nanotubes are mixed with the graphene and the calcium silicate to obtain modified carbon nanotubes.

[0078] In some embodiments, the step of mixing the multi-walled carbon nanotubes with the graphene and the calcium silicate to obtain modified carbon nanotubes includes: mixing the multi-walled carbon nanotubes, the graphene, the calcium silicate, a binder and a solvent, and then performing ball milling treatment to obtain a mixed slurry, and drying the mixed slurry to obtain the modified carbon nanotubes.

[0079] As an example, the multi-walled carbon nanotubes are dispersed in a solvent, then the graphene and the calcium silicate are added, and then an appropriate amount of binder is added, and the mixture is ball milled after being uniformly mixed. The solvent here can be water, ethanol or the like. The amount of the binder added is 0.5-1wt% of the total mass of the multi-walled carbon nanotubes, the graphene and the calcium silicate. As an example, the amount of the binder added can be any one of 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt% and 1.0wt% of the total mass of the multi-walled carbon nanotubes, the graphene and the calcium silicate, or a range value between any two of them. In some embodiments, the binder includes at least one of polyethylene glycol, polyvinyl alcohol, polyacrylic acid, polyvinylpyrrolidone, polyvinylidene fluoride and polyurethane binder. Adding the above binder can make the multi-walled carbon nanotubes, the graphene and the calcium silicate bind together, so as to modify the multi-walled carbon nanotubes with the graphene and the calcium silicate and improve the interface energy between the multi-walled carbon nanotubes and the resin base material.

[0080] In some embodiments, before the multi-walled carbon nanotubes are dispersed in the solvent, the multi-walled carbon nanotubes are first dispersed in a silane coupling agent solution, and then ball milled and dried after being uniformly mixed. In this way, the compounding of the multi-walled carbon nanotubes with the graphene and the calcium carbonate can be more uniform and stable.

[0081] In some embodiments, the ball milling treatment conditions include: the grinding medium uses zirconia balls and / or agate balls with a diameter of 0.5-1.0mm; the filling rate of the grinding medium is 60%-85%; and the stirring rate is 500-900r / min. After ball milling, a mixed slurry is obtained, and the mixed slurry is spray dried to form granular material of the modified carbon nanotubes with a particle size of 0.1-1mm.

[0082] Step S2:

[0083] In some embodiments, the step of dispersing the modified carbon nanotubes and the high impact polystyrene to obtain the carbon nanotube composite material comprises: dispersing the modified carbon nanotubes and the high impact polystyrene in tetrahydrofuran, and obtaining the carbon nanotube composite material after removing the solvent under vacuum.

[0084] As an example: a certain amount of modified carbon nanotubes is ultrasonically dispersed in a tetrahydrofuran solution, and after uniform dispersion, it is added to a tetrahydrofuran solution in which high impact polystyrene is dissolved, and ultrasonic dispersion is performed for 0.5-2 hours. After vacuum drying to remove the solvent, a modified carbon nanotube composite material is obtained.

[0085] In some embodiments, before the dispersing treatment, the high impact polystyrene is first crushed into a powder with a particle size of ≤2000 mesh at an ultra-low temperature of less than -190°C.

[0086] In some embodiments, before the dispersing treatment, the modified carbon nanotubes are first crushed to a particle size of Dmax≤300μm by airflow crushing process. Crushing the high impact polystyrene and the modified carbon nanotubes into a powder with a smaller particle size can better improve the dispersibility of the carbon nanotubes in the high impact polystyrene and improve the compounding efficiency.

[0087] Step S3:

[0088] The carbon nanotube composite material is mixed with polyphenyl ether, toughening agent, dispersant, inorganic filler and antioxidant, and then melt-extruded and granulated to obtain a polyphenyl ether conductive composite material.

[0089] In some embodiments, before melt-extrusion granulation, the toughening agent, dispersant, inorganic filler and antioxidant are mixed in a high-speed mixer with a rotation speed of 200-400 rpm for 3-10 min to obtain a mixed additive, and then the modified carbon nanotube composite material, polyphenyl ether resin and mixed additive are discharged from three different loss-on- drying balances, respectively, and melt-extrusion granulation is performed through a twin-screw extruder at an extrusion temperature of 250-300°C, with a main machine rotation speed of 400-1000 rpm / min.

[0090] In some embodiments, the process conditions for melt-extrusion granulation include an extrusion temperature of 250-300°C, a main machine rotation speed of 400-1000 rpm / min, and melt-extrusion granulation by a double-screw extruder. The double-screw extruder includes, in sequence, a melting section, a pressing section, a shearing section, a pressurizing section, a melting exhaust section, a pressing section, a shearing section, a pressurizing section, a melting exhaust section, and a die head. The set process conditions for the double-screw extruder are as follows: melting section: 250-270°C; pressing section: 270-300°C; shearing section: 270-290°C; pressurizing section: 270-290°C; melting exhaust section: 270-290°C; pressing section: 270-290°C; shearing section: 270-280°C; pressurizing section: 270-290°C; melting exhaust section: 280-290°C; die head temperature: 290-300°C; main machine rotation speed: 400-1000 rpm / min; and vacuum degree: ≤-0.05 MPa.

[0091] The following is described in connection with specific embodiments.

[0092] Embodiment 1

[0093] The embodiment provides a polyphenyl ether conductive composite material, which includes the following components in parts by weight:

[0094] Polyphenyl ether 46.8 parts;

[0095] Carbon nanotube composite material 20 parts;

[0096] Toughening agent 1 part;

[0097] Dispersant 2 parts;

[0098] Talc 30 parts;

[0099] Antioxidant 1010 0.2 parts.

[0100] The carbon nanotube composite material includes modified carbon nanotubes and high-impact polystyrene, and the modified carbon nanotubes include multi-walled carbon nanotubes, graphene, and calcium silicate. The mass ratio of the multi-walled carbon nanotubes, graphene, and calcium silicate in the modified carbon nanotubes is 1:0.1:0.5, and the mass ratio of the modified carbon nanotubes to the high-impact polystyrene in the carbon nanotube composite material is 10:90. The multi-walled carbon nanotubes have a length-diameter ratio of (7000-8000):1 and a length of 80-90 μm. The toughening agent is a maleic anhydride grafted hydrogenated styrene-butadiene-styrene copolymer. The dispersant is polyvinylpyrrolidone.

[0101] The preparation method of the polyphenyl ether conductive composite material includes the following steps:

[0102] S1: 5 parts by weight of multi-walled carbon nanotube powder was dispersed in ethanol, 0.5 parts by weight of graphene and 2.5 parts by weight of calcium silicate were added, 0.08 parts by weight of a binder polyethylene glycol was added, and the mixture was ball milled after being uniformly mixed. The grinding medium was 0.5-1.0 mm zirconia balls, the grinding medium filling rate was 65%, and the stirring rate was 700 r / min. A mixed slurry was obtained, and the mixed slurry was spray dried to obtain modified carbon nanotubes with a particle size of 0.1-1 mm.

[0103] S2: 5 parts by weight of modified carbon nanotubes were ultrasonically dispersed in a tetrahydrofuran solution, and after being uniformly dispersed, they were added to a tetrahydrofuran solution in which 95 parts by weight of high-impact polystyrene was dissolved, and ultrasonic dispersion was performed for 1 hour. After vacuum drying to remove the solvent, a modified carbon nanotube composite material was obtained.

[0104] S3: The modified carbon nanotube composite material, polyphenyl ether, toughening agent, dispersant, inorganic filler and antioxidant were discharged from the loss weight scale, and were melt-extruded and pelletized through a twin-screw extruder at an extrusion temperature of 250-300℃ and a main machine rotation speed of 700 rpm / min to obtain a polyphenyl ether conductive composite material.

[0105] The above-mentioned twin-screw extruder sequentially includes a melting section, a pressing section, a shearing section, a pressurizing section, a melting exhaust section, a pressing section, a shearing section, a pressurizing section, a melting exhaust section and a machine head. The set process conditions of the twin-screw extruder are as follows: melting section: 260℃; pressing section: 280℃; shearing section: 280℃; pressurizing section: 280℃; melting exhaust section: 280℃; pressing section: 280℃; shearing section: 280℃; pressurizing section: 280℃; melting exhaust section: 290℃; machine head temperature: 300℃; main machine rotation speed: 700 rpm / min, vacuum degree: ≤-0.05 MPa.

[0106] Example 2

[0107] The present embodiment provides a polyphenyl ether conductive composite material, which comprises the following components by weight:

[0108] Polyphenyl ether 46.8 parts;

[0109] Carbon nanotube composite material 20 parts;

[0110] Toughening agent 1 part;

[0111] Dispersant 2 parts;

[0112] Talc 30 parts;

[0113] Antioxidant 1010 0.2 parts.

[0114] The carbon nanotube composite material comprises modified carbon nanotubes and high impact polystyrene, and the modified carbon nanotubes comprise multi-walled carbon nanotubes, graphene and calcium silicate; the mass ratio of the multi-walled carbon nanotubes, graphene and calcium silicate in the modified carbon nanotubes is 1:0.2:1; and the mass ratio of the modified carbon nanotubes to the high impact polystyrene in the carbon nanotube composite material is 20:80. The specifications of the multi-walled carbon nanotubes, the toughening agent and the dispersant are the same as those in Embodiment 1.

[0115] The preparation method is basically the same as that in Embodiment 1, except that in step S1, 5 parts by weight of multi-walled carbon nanotube powder is dispersed in a solvent, 1 part by weight of graphene and 5 parts by weight of calcium silicate are added, 0.11 parts by weight of a binder is added, and the mixture is uniformly mixed and then ball milled.

[0116] Embodiment 3

[0117] The present embodiment provides a polyphenyl ether conductive composite material, which comprises the following components in parts by weight:

[0118] Polyphenyl ether 46.8 parts;

[0119] Carbon nanotube composite material 20 parts;

[0120] Toughening agent 1 part;

[0121] Dispersant 2 parts;

[0122] Talc 30 parts;

[0123] Antioxidant 1010 0.2 parts.

[0124] The carbon nanotube composite material comprises modified carbon nanotubes and high impact polystyrene, and the modified carbon nanotubes comprise multi-walled carbon nanotubes, graphene and calcium silicate; the mass ratio of the multi-walled carbon nanotubes, graphene and calcium silicate in the modified carbon nanotubes is 1:0.5:2; and the mass ratio of the modified carbon nanotubes to the high impact polystyrene in the carbon nanotube composite material is 10:90. The specifications of the multi-walled carbon nanotubes, the toughening agent and the dispersant are the same as those in Embodiment 1.

[0125] The preparation method is basically the same as that in Embodiment 1, except that in step S1, 5 parts by weight of multi-walled carbon nanotube powder is dispersed in a solvent, 2.5 parts by weight of graphene and 10 parts by weight of calcium silicate are added, 0.17 parts by weight of a binder is added, and the mixture is uniformly mixed and then ball milled.

[0126] Embodiment 4

[0127] The embodiment provides a polyphenyl ether conductive composite material, which comprises the following components in parts by weight:

[0128] polyphenyl ether 46.8 parts;

[0129] carbon nanotube composite material 20 parts;

[0130] toughening agent 1 part;

[0131] dispersant 2 parts;

[0132] talc 30 parts;

[0133] antioxidant 1010 0.2 parts.

[0134] The carbon nanotube composite material comprises modified carbon nanotubes and high-impact polystyrene, and the modified carbon nanotubes comprise multi-walled carbon nanotubes, graphene and calcium silicate; the mass ratio of the multi-walled carbon nanotubes, the graphene and the calcium silicate in the modified carbon nanotubes is 1:0.2:1, and the mass ratio of the modified carbon nanotubes to the high-impact polystyrene in the carbon nanotube composite material is 20:80. The multi-walled carbon nanotubes, the toughening agent and the dispersant are selected in the same manner as in Embodiment 1.

[0135] The preparation method is basically the same as that in Embodiment 2, except that in step S2, 5 parts by weight of the modified carbon nanotubes are ultrasonically dispersed in a tetrahydrofuran solution, and after being uniformly dispersed, are added to a tetrahydrofuran solution in which 100 parts by weight of high-impact polystyrene is dissolved, and are ultrasonically dispersed for 1 hour. After vacuum drying to remove the solvent, a modified carbon nanotube composite material is obtained.

[0136] Embodiment 5

[0137] The embodiment provides a polyphenyl ether conductive composite material, which comprises the following components in parts by weight:

[0138] polyphenyl ether 68 parts;

[0139] carbon nanotube composite material 27 parts;

[0140] toughening agent 2 parts;

[0141] dispersant 3 parts;

[0142] talc 30 parts;

[0143] Antioxidant 1010 0.5 parts.

[0144] The carbon nanotube composite material comprises modified carbon nanotubes and high impact polystyrene, and the modified carbon nanotubes comprise multi-walled carbon nanotubes, graphene and calcium silicate; the mass ratio of the multi-walled carbon nanotubes, graphene and calcium silicate in the modified carbon nanotubes is 1:0.2:1, and the mass ratio of the modified carbon nanotubes to the high impact polystyrene in the carbon nanotube composite material is 20:80. The multi-walled carbon nanotubes, the toughening agent and the dispersant are selected in the same manner as in Embodiment 1.

[0145] The preparation method is basically the same as that in Embodiment 2, except that the feeding amount of each component in step S2 is different.

[0146] Comparative Example 1

[0147] The present comparative example provides a polyphenyl ether conductive composite material comprising the following components by weight:

[0148] Polyphenyl ether 46.8 parts;

[0149] High impact polystyrene 18 parts;

[0150] Multi-walled carbon nanotubes 2 parts;

[0151] Toughening agent 1 part;

[0152] Dispersant 2 parts;

[0153] Talc 30 parts;

[0154] Antioxidant 1010 0.2 parts.

[0155] The multi-walled carbon nanotubes, the toughening agent and the dispersant are selected in the same manner as in Embodiment 1.

[0156] The preparation method comprises the following steps:

[0157] The high impact polystyrene is crushed into a powder with a particle size of ≤2000 mesh under an ultra-low temperature environment below -190℃; the multi-walled carbon nanotubes are crushed to a particle size of Dmax≤300μm through an airflow crushing process;

[0158] The toughening agent, dispersant, talc and antioxidant were placed in a high-speed mixer with a rotation speed of 300 rpm for 5 min to obtain a mixing aid. The high-impact polystyrene, multi-walled carbon nanotubes and PPO resin were discharged from four different loss-on-ignition scales, and were melt-extruded and pelletized by a twin-screw extruder at an extrusion temperature of 250-300°C and a main machine rotation speed of 400-1000 rpm / min. The set process conditions of the twin-screw extruder were the same as in Example 1.

[0159] Comparative Example 2

[0160] The present comparative example provides a polyphenylene ether conductive composite material, which comprises the following components by weight:

[0161] Polyphenylene ether 46.8 parts;

[0162] Carbon nanotube composite 20 parts;

[0163] Toughening agent 1 part;

[0164] Dispersant 2 parts;

[0165] Talc 30 parts;

[0166] Antioxidant 1010 0.2 parts.

[0167] The carbon nanotube composite comprises modified carbon nanotubes and high-impact polystyrene, and the modified carbon nanotubes only contain multi-walled carbon nanotubes and graphene, the mass ratio of the multi-walled carbon nanotubes and the graphene being 1:0.2; the mass ratio of the modified carbon nanotubes to the high-impact polystyrene being 5:95. The multi-walled carbon nanotubes, the toughening agent and the dispersant are selected in the same manner as in Example 1.

[0168] The preparation method of the above polyphenylene ether conductive composite material is basically the same as in Example 1, except that the preparation step of the modified carbon nanotubes is different.

[0169] The preparation step S1 of the modified carbon nanotubes of the present comparative example is as follows: 5 parts by weight of multi-walled carbon nanotube powder is dispersed in a solvent, 1 part by weight of graphene is added, 0.06 parts by weight of a binder is added, and the mixture is uniformly mixed and ball milled. The grinding medium is 0.5-1.0 mm zirconia balls, the grinding medium filling rate is 65%, and the stirring speed is 700 r / min. The mixed slurry is obtained, and the modified carbon nanotubes are obtained by spray drying the mixed slurry, with a particle size of 0.1-1 mm.

[0170] Performance test

[0171] The polyphenyl ether conductive composite materials of each of the above examples and comparative examples were compression molded into parts, injection molded into test bars according to standard dimensions, and then surface resistivity and wear resistance tests were performed.

[0172] Surface resistivity (unit: Ω / Sq): The test method for surface resistivity used the direct current comparison method, and the test equipment and measurement error conformed to the provisions of GB / T 3048.5.

[0173] Wear amount: The wear resistance of the test material was tested according to the provisions of GB / T 3960-2016 “Plastics - Sliding Friction and Wear Testing Method”.

[0174] Table 1

[0175] Test item Example 1 Example 2 Example 3 Example 4 Example 5 Comparative example 1 Comparative example 2 Surface resistivity Ω / Sq. 9.1 x 108 9.5 x 106 8.4 x 108 7.2 x 106 2.8 x 107 1.2 x 10107.7 x 109 Wear amount 0.016% 0.015% 0.017% 0.019% 0.018% 0.31% 0.26%

[0176] As shown in Table 1, compared with the comparative examples, the surface resistivity of the polyphenyl ether conductive composite materials of each example is significantly lower, indicating that the antistatic effect of each example polyphenyl ether conductive composite material is better.

[0177] From the wear amount data, it can be seen that compared with the comparative examples, the wear amount of the polyphenyl ether conductive composite materials of each example is significantly lower, indicating that the use of carbon nanotube composite material instead of traditional carbon-based conductive agent as conductive filler added to the resin matrix can improve the wear resistance of the material, thereby achieving the effect of reducing dust.

[0178] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A polyphenylene ether conductive composite material, characterized in that: The composition comprises the following components in parts by weight: 40-70 parts of polyphenylene ether; 10-30 parts of carbon nanotube composite material; 1~3 parts of toughening agent; 2~4 parts of dispersant; 20-30 parts of inorganic filler; 0.1~1 part of antioxidant; The carbon nanotube composite material comprises modified carbon nanotubes and high-impact polystyrene, and the modified carbon nanotubes comprise multi-walled carbon nanotubes, graphene and calcium silicate.

2. The polyphenylene ether conductive composite material according to claim 1, wherein The mass ratio of the modified carbon nanotubes to the high-impact polystyrene is (10-20):(80-90).

3. The polyphenylene ether conductive composite material according to claim 1 or 2, wherein: The mass ratio of the multi-walled carbon nanotubes, the graphene and the calcium silicate is 1:(0.1-0.5):(0.5-2).

4. The polyphenylene ether conductive composite material according to claim 1 or 3, wherein: The multi-walled carbon nanotubes have at least one of the following (1)-(5): (1) The multi-walled carbon nanotubes have an inner diameter of 1-2 nm, an outer diameter of 8-25 nm, a length of 1-100 μm, an aspect ratio of 5000-10000:1, and a bulk density of 0.15-0.4 g / cm 3 , with a specific surface area of ​​190~270m 2 / g; (2) The thermal conductivity of the multi-walled carbon nanotubes is 300-6000 W / mk; (3) The initial decomposition temperature of the multi-walled carbon nanotubes is 500-600°C; (4) The particle size of the multi-walled carbon nanotubes is D97≤50μm and the particle size Dmax≤300μm; (5) The powder resistivity of the multi-walled carbon nanotubes is 30-60 mΩ·cm; (6) The Raman spectrum intensity of the multi-walled carbon nanotubes is D / I G ≤1.

2.

5. The polyphenylene ether conductive composite material according to claim 1 or 2, wherein: The weight average molecular weight of the high impact polystyrene is 150,000 to 300,000 g / mol.

6. The polyphenylene ether conductive composite material according to claim 1, wherein The inorganic filler includes at least one of talc, calcium carbonate, silica fume, mica powder, kaolin, wollastonite, and attapulgite; and the particle size of the inorganic filler is 1000-3000 mesh.

7. The polyphenylene ether conductive composite material according to claim 1, wherein The antioxidant includes at least one of a hindered phenol antioxidant and a phosphite antioxidant.

8. The polyphenylene ether conductive composite material according to any one of claims 1 to 7, wherein: The polyphenylene ether conductive composite material has at least one of the following (1)-(3): (1) The surface resistivity of the polyphenylene ether conductive composite material is 10 6 ~10 8 Ω / sq; (2) The polyphenylene ether conductive composite material has a melt index of 6 to 13 g / 10 min under the test conditions of 300° C. and 10 kg; (3) The density of the polyphenylene ether conductive composite material is 1.07~1.1g / cm 3 .

9. The method for preparing the polyphenylene ether conductive composite material according to any one of claims 1 to 8, wherein: The following steps are involved: Mixing the multi-walled carbon nanotubes with the graphene and the calcium silicate to obtain the modified carbon nanotubes; Dispersing the modified carbon nanotubes and the high-impact polystyrene to obtain the carbon nanotube composite material; The carbon nanotube composite material is mixed with the polyphenylene ether, the toughening agent, the dispersant, the inorganic filler and the antioxidant, and then melt-extruded and granulated to obtain the polyphenylene ether conductive composite material.

10. The method for preparing the polyphenylene ether conductive composite material according to claim 9, wherein: The step of mixing the multi-walled carbon nanotubes with the graphene and the calcium silicate to obtain the modified carbon nanotubes includes: mixing the multi-walled carbon nanotubes, the graphene, the calcium silicate, a binder and a solvent, then ball milling to obtain a mixed slurry, and drying the mixed slurry to obtain the modified carbon nanotubes.

11. The method for preparing the polyphenylene ether conductive composite material according to claim 10, wherein: The conditions for the ball milling treatment include: the grinding media include zirconia balls and / or agate balls; the size of the grinding media is 0.5-1.0 mm; the filling rate of the grinding media is 60%-85%; and the stirring rate is 500-900 r / min.

12. The method for preparing the polyphenylene ether conductive composite material according to claim 9, wherein: The step of dispersing the modified carbon nanotubes and the high-impact polystyrene to obtain the carbon nanotube composite material includes: adding the modified carbon nanotubes and the high-impact polystyrene into tetrahydrofuran for dispersion, and removing the solvent in vacuo to obtain the carbon nanotube composite material.

13. The method for preparing the polyphenylene ether conductive composite material according to claim 9, wherein: The process conditions of the melt extrusion granulation include: an extrusion temperature of 250-300° C., a main engine speed of 400-1000 rpm / min, and melt extrusion granulation through a twin-screw extruder.